what are biomaterials

Biomaterials are biocompatible materials, natural or man-made, that comprise a whole or a part of a living structure or biomedical device that performs, augments, or replaces a natural function. Biomaterials are most often engineered for medical, biotechnology and pharmaceutical applications. Biomaterials include hydroappatite, cadaver bone, wound dressing materials, drug delivery vehicles, transdermal films, and titanium, bioceramics. Applications for biomaterials may include dental implants, dental fillings, dental caps and bridges, surgical instruments, stents, blood bags, intravenous tubing, prostheses, and artificial limbs. Biomaterials have low or no toxicity or cytotoxicity. Cytotoxicity indicates cell killing ability or characteristic. Cytotoxins are poisonous to cells. Biomaterials or biocompatible materials do not consist of, release or convert to toxic agents. Biocompatible materials can integrate into the body. For example, bone can osteointegrate or grow up to and bond to pure titanium. Biomechanical considerations are also important in determining the biocompatibility of materials. For instances, carbon has a much closer modulus to bone than titanium, so bone will not be stress shielded and atrophy as much for two prostheses with the same dimensions and design. Many materials are considered biocompatible or biomaterials, such as titanium; certain stainless steels; tantulum; silver, gold and other precious metals; certain polymers; bioeceramics; aluminum oxide ceramics; cobalt- chrome-moly alloys; certain composites; hydroxyapatite; natural materials such as cadaver bone; animal derived products; wound or burn dressing materials; grafting and scaffolding materials; corneal lens replacement materials; bioglass; platelet gel; tissue sealants; and suture materials. Other, unlisted materials may also be considered biomaterials. Special features available with biomaterials may include being or having inert and corrosion resistant to body fluids; modulus tailored to match bone modulus; low toxicity to cells; pig valves for heart operations; osteostimulative materials; growth enhancing materials; cartilage replacement fibers; elastomeric materials for facial surgery; plastic surgery materials; bioactive wound healing materials; oral regeneration materials; bone grafting materials; and biosurgical materials. Other, unlisted features for biomaterials may also be available.